Penetration of human skin by the cercariae of Schistosoma mansoni : an investigation of the effect of multiple cercarial applications

It has previously been postulated that L-arginine emitted by penetrating Schistosoma mansoni cercariae serves as an intraspecific signal guiding other cercariae to the penetration site. It was suggested that penetrating in groups offers a selective advantage. If this hypothesis is correct and group penetration at one site on the host offers an advantage, it would follow that at such a site, successive groups of cercariae would be able to penetrate skin in either greater numbers or at a faster rate. This prediction was tested by the use of an in vitro model of cercarial penetration based on the Franz cell and using human skin. It was demonstrated that there was no increase in the percentage of cercariae able to penetrate the skin with subsequent exposures. Consequently, it seems unlikely that the release of L-arginine by cercariae during penetration could have evolved as a specific orientation system based on a selective advantage offered by group penetration.Peer reviewe

Ultrafast Dynamics of Vibrational Symmetry Breaking in a Charge-ordered Nickelate

The ability to probe symmetry breaking transitions on their natural time scales is one of the key challenges in nonequilibrium physics. Stripe ordering represents an intriguing type of broken symmetry, where complex interactions result in atomic-scale lines of charge and spin density. Although phonon anomalies and periodic distortions attest the importance of electron-phonon coupling in the formation of stripe phases, a direct time-domain view of vibrational symmetry breaking is lacking. We report experiments that track the transient multi-THz response of the model stripe compound La$_{1.75}$Sr$_{0.25}$NiO$_{4}$, yielding novel insight into its electronic and structural dynamics following an ultrafast optical quench. We find that although electronic carriers are immediately delocalized, the crystal symmetry remains initially frozen - as witnessed by time-delayed suppression of zone-folded Ni-O bending modes acting as a fingerprint of lattice symmetry. Longitudinal and transverse vibrations react with different speeds, indicating a strong directionality and an important role of polar interactions. The hidden complexity of electronic and structural coupling during stripe melting and formation, captured here within a single terahertz spectrum, opens new paths to understanding symmetry breaking dynamics in solids.Comment: 21 pages, 4 figures; updated version with journal re

Drug utilization study of antimicrobial agents in patients of neonatal sepsis in neonatal intensive care unit at a tertiary care hospital in western part of India

Background: Neonatal sepsis is one of the major causes of death and morbidity among neonates in India; however, studies related to neonatal sepsis are somewhat in limited numbers. Furthermore, time to time sensitivity and efficacy of various antimicrobial agents (AMA) change which necessitates studies related to antimicrobial drug utilization in hospitals. The objective of present study was to evaluate the pattern of use of AMAs in neonatal sepsis at the neonatal intensive care unit (NICU) at a tertiary care hospital in western part of India.Methods: It was a prospective cross-sectional study conducted over a period of 6-month duration in NICU at tertiary care hospital. Data were collected and analyzed.Results: It has been observed that 57.67% patients were pre-term, 42.32% full term; 23.28% were of normal birth weight, 58.73% low birth weight and 15.34% were very low birth weight. In 48.7% of patients, two different antibiotics were prescribed while in 40.1% of patients three different antibiotics were prescribed. A total number of antibiotics prescribed were 499, per patient 2.78 antibiotics were prescribed. Amikacin was used in 73.01% cases while cefotaxime was used in 64.55% of cases. Piperacilin + tazobactam combination was used in 41.26% cases. In 50.9% cases, antibiotics were prescribed by generic name.Conclusion: Antibiotic resistance is increasing due to the irrational prescribing habits of physicians, leading to increasing morbidity, mortality and treatment costs. Therefore, the medical professionals as well as government personnel who are related to the health sector need to understand that antibiotics are precious and finite resources. The remedy of this situation requires that regular educational awareness programs should be conducted in hospitals at a regular basis

Rethinking Committee Work in the Research Enterprise: The Case of Regenerative Gatekeeping

Committees touch nearly every facet in the science, technology, engineering, and mathematics research enterprise. However, the role of gatekeeping through committee work has received little attention in Earth and space sciences. We propose a novel concept called, “regenerative gatekeeping” to challenge institutional inertia, cultivate belonging, accessibility, justice, diversity, equity, and inclusion in committee work. Three examples, a hiring committee process, a seminar series innovation, and an awards committee, highlight the need to self-assess policies and practices, ask critical questions and engage in generative conflict. Rethinking committee work can activate distributed mechanisms needed to promote change

Lipid and protein content profiling of isolated native autophagic vesicles

Autophagy is responsible for clearance of an extensive portfolio of cargoes, which are sequestered into vesicles, called autophagosomes, and are delivered to lysosomes for degradation. The pathway is highly dynamic and responsive to several stress conditions. However, the phospholipid composition and protein contents of human autophagosomes under changing autophagy rates are elusive so far. Here, we introduce an antibody-based FACS-mediated approach for the isolation of native autophagic vesicles and ensured the quality of the preparations. Employing quantitative lipidomics, we analyze phospholipids present within human autophagic vesicles purified upon basal autophagy, starvation, and proteasome inhibition. Importantly, besides phosphoglycerides, we identify sphingomyelin within autophagic vesicles and show that the phospholipid composition is unaffected by the different conditions. Employing quantitative proteomics, we obtain cargo profiles of autophagic vesicles isolated upon the different treatment paradigms. Interestingly, starvation shows only subtle effects, while proteasome inhibition results in the enhanced presence of ubiquitin-proteasome pathway factors within autophagic vesicles. Thus, here we present a powerful method for the isolation of native autophagic vesicles, which enabled profound phospholipid and cargo analyses

Estrogen Prevents Oxidative Damage to the Mitochondria in Friedreich's Ataxia Skin Fibroblasts

Estrogen and estrogen-related compounds have been shown to have very potent cytoprotective properties in a wide range of disease models, including an in vitro model of Friedreich's ataxia (FRDA). This study describes a potential estrogen receptor (ER)-independent mechanism by which estrogens act to protect human FRDA skin fibroblasts from a BSO-induced oxidative insult resulting from inhibition of de novo glutathione (GSH) synthesis. We demonstrate that phenolic estrogens, independent of any known ER, are able to prevent lipid peroxidation and mitochondrial membrane potential (ΔΨm) collapse, maintain ATP at near control levels, increase oxidative phosphorylation and maintain activity of aconitase. Estrogens did not, however, prevent BSO from depleting GSH or induce an increased expression level of GSH. The cytoprotective effects of estrogen appear to be due to a direct overall reduction in oxidative damage to the mitochondria, enabling the FRDA fibroblast mitochondria to generate sufficient ATP for energy requirements and better survive oxidative stress. These data support the hypothesis that phenol ring containing estrogens are possible candidate drugs for the delay and/or prevention of FRDA symptoms

Formation and preservation of greigite (Fe₃S₄) in sediments from the Santa Barbara Basin: implications for paleoenvironmental changes during the past 35 ka

Diagenetic processes are known to modify sedimentary records, but they can also reveal important paleoenvironmental changes. Here we investigate variations in sedimentary iron diagenesis and depositional environments for the last 35 ka by analyzing the rock magnetic and geochemical properties of two sediment cores collected in the Santa Barbara Basin (California). In organic-rich sediments, early diagenesis often leads to partial dissolution of detrital iron oxides and stepwise formation of authigenic pyrite (FeS2). The pyritization process takes place following several geochemical pathways, sometimes involving intermediate iron sulfide species such as greigite (Fe3S4). Sedimentary conditions in the basin appear to have recurrently favored preservation of greigite (identified by its magnetic properties) and inhibited its complete transformation into pyrite. The Holocene interval contains a series of centimeter-thick greigite-bearing layers that are associated with large flood deposits, which are known in the basin as ‘‘gray layers.’’ We propose that greigite preservation was enabled in these sediments by their relative enrichment in reactive iron over organic matter and/or hydrogen sulfide (because of their high ratio of terrigenous over organic material), which limited pyritization reactions. Within the glacial deposits, formation and preservation of meter-thick greigite layers occurred in terrigenous-rich and organic-poor sedimentary layers and is proposed to result from a similar diagenetic process to that in the Holocene greigite-bearing layers (dominance of reactive iron over organic matter and/or HS�). The terrigenous enrichments in the glacial greigite-bearing layers are probably related to climatic or sea level changes because they occur at times of massive iceberg releases in the North Atlantic, the so-called Heinrich events

Importance of Extranuclear Estrogen Receptor-α and Membrane G Protein–Coupled Estrogen Receptor in Pancreatic Islet Survival

International audienc

Cloning of a novel malignant melanoma-derived growth-regulatory protein, MIA

Growth and progression of malignant melanoma cells is influenced by a complex network of growth-stimulating and -inhibiting factors produced by both the tumor cells and the local environment. Here we report the purification and molecular cloning of a novel growth regulating protein, designated melanoma inhibitory activity (MIA) and provide a preliminary functional characterization. MIA is translated as a 131-amino acid precursor and processed into a mature 107-amino acid protein after cleavage of a putative secretion signal. A murine complementary DNA was isolated that encoded a MIA-protein with 88% amino acid identity. MIA is secreted into the culture supernatant by several malignant melanoma cell lines as an M(r) 11,000 autocrine growth factor and acts as a potent tumor cell growth inhibitor for malignant melanoma cells and some other neuroectodermal tumors, including gliomas. MIA has no homology to any other known protein and, therefore, represents a novel type of growth-regulatory factor. Furthermore, we describe a molecular approach to express functionally active MIA in Escherichia coli, which might be attractive as a future antitumor therapeutical substance